This is C-SPAN's Lectures in History podcast.

This week, Emory University professor Felix Harcourt teaches a class on how conspiracy theories about UFOs have shaped American culture.

And how public opinion about extraterrestrials from the late 1940s through the course of the 20th century

has often paralleled societal anxieties.

Let's start with a question that I'm sure nobody will have any problem having their

answer recorded for television for.

Show of hands, how many people believe alien life exists?

Yeah, pretty decent number of people.

I'm going to throw in there as well.

But I think so.

Stephen Hawking thinks so.

In a giant universe, there is distinctly a probability that somewhere alien life has evolved and, you know,

probably looks pretty different from us, but it might be out there. Slightly different question.

How many of us believe that aliens have visited Earth?

Sergio, the only man with the strength of his convictions. I appreciate that.

So here's a question.

Is the idea that aliens have visited Earth in and of itself a conspiracy theory?

Sergio?

I don't believe so.

No, why not?

Well, I mean, if you take into consideration the fact that we're trying to go to Mars,

we would technically be alien life there, so the fact that another life form, say that has become intelligent enough

...